TUPLE: point x y z ;

: xyz ( point -- x y z )
    [ x>> ] [ y>> ] [ z>> ] tri ; inline

: change-xyz ( point obj x: ( x obj -- x' ) y: ( y obj -- y' ) z: ( z obj -- z' ) -- point )
    tri-curry [ change-x ] [ change-y ] [ change-z ] tri* ; inline

: init-point ( n -- point )
    ! TODO
    dup dup point boa ;
    ;

: make-points ( len -- points )
    iota [ init-point ] map-index ;